Slicer knife sharpener



Aug. 16, 1955 J. D. BROWN 2,715,305

SLICER KNIFE SHARPENER Filed Feb. 28, 1952 2 Sheets-Sheet l 3 nventorJAMES 0 BROWN attorney;

g- 15, 1955 J. D. BROWN 2,715,305

SLICER KNIFE SHARPENER Filed Feb. 28, 1952 2 Sheets-Sheet 2 Zmventor JAMES [7. BROWN (Ittornegi United States Patent sLIcER KNIFE SHARPENERJames D. Brown, Toledo, Ohio, assignor to Toledo Scale Company, Toledo,Ohio, a corporation of New Jersey Application February 28, 1952, SerialNo. 273,820

6 Claims. (Cl. 51-248) This invention relates to slicing machines, andin particular to a device for sharpening the rotary knives thereof.

Prior art sharpening devices for the knives of slicing machines havebeen, in general, of the spring or cam engageable type having a grindingwheel and a honing wheel arranged to simultaneously contact oppositesides of the cutting edge of the knife. While, for the most part, priorart sharpening devices of this type have performed satisfactorily,certain disadvantages have been inherent in having the sharpening wheelsmechanically engageable with the knife, and in having them contact theknife simultaneously.

The instant invention provides a sharpening device for the rotary knifeof a slicing machine which has finger-engageable grinding and honingwheels, thereby allowing sharpening to take place by touch, and alsoprovides independently operated grinding and honing wheels which allowfor either or both to be in contact with its respective side of theknife at one time.

it is a primary object of this invention to provide for the rotary knifeof a slicing machine a sharpening unit with individual grinding andhoning wheels which are finger-engageable with the knift eitherseparately or together.

A further object is to provide a storage space for a detachable slicerknife sharpener which eliminates the necessity of having a bulgeprotruding from the portion of the machine adjacent the knife.

Another object is the provision of finger-engageable grinding and honingwheels for sharpening the cutting edge of a circular knife which permitsthe sharpening to take place by human touch.

Still another object is the provision of an improved type of sharpeningmechanism for the rotary knife of a slicing mach ne which permitsgreater ease of operation.

Other objects and advantages will be apparent from the followingdescription, in which reference is had to the accompanying drawings.

According to the invention, a knife sharpening unit comprisingindependently operated grinding and honing wheels is adapted to beremovably attached to the gauge plate of a slicer with the wheelsarranged to engage opposite sides of the marginal area of a knife tosharpen the knife. The wheels are engaged with the knife by means of afinger-depressible lever operably connected to each wheel, said leversboth being depressible in the same directiomby two fingers of one hand.Either wheel may be operated separately or both simultaneously, therebycausing either or both wheels to engage the knife as desired.

in the drawings:

Figure I is a view in perspective of a slicing machine showing theposition occupied by the sharpening unit of this invention during asharpening operation.

Figure II is a view on an enlarged scale looking down upon thesharpening unit and further showing its position relative to the knifeand the gauge plate.

Figure III is an elevational View of the sharpening unit taken along theline III-Ill of Figure II.

Figure IV is an elevational view of the grinding mechanism of thesharpening unit taken substantially along the line IVIV of Figure II.

Figure V is an isometric View of the spindle arrangement which istypical of both the grinding and honing mechanisms.

Figure V1 is an elevational view with parts broken away and parts insection of the storage location for the sharpening unit when the unit isdetached from the gauge plate.

Referring to Figure I, a slicing machine of the general type in whichthe instant invention is shown consists of a housing 1 above which liesan inclined rotary circular knife 2. Overlying the face of the knife isa knife guard plate 3 against which a substance being sliced rests afterit has passed the cutting edge of the knife 2. Lying in a planesubstantially parallel to the plane of the guard plate 3 and adjacentthe cutting edge of the knife 2 is a gauge plate 4. The gauge plate 4 islaterally adjustable with respect to the plane of the knife 2 tocondition the slicer for cutting slices of difierent thicknesses.

A carriage 5 reciprocates along one side of the housing 1 on a track 6to carry the substance to be sliced past the cutting edge of the knife.A V-shaped trough or substance support '7 constitutes the upper portionof the carriage 5 and is inclined to the housing 1 to permit gravityfeeding of the substance carried thereby.

A knife sharpening unit 8, when mounted to sharpen the cutting edge ofthe knife 2., is detachably secured to the gauge plate 4 by means of athumb screw 9 which passes through a slotted portion 19 of the gaugeplate and is threaded into an upright frame 11 of the unit 8.

The frame 11 has a hat base portion 12 which rests against the gaugeplate 4, and further has a flange or lip 13 projecting downwardly fromone side of the base portion to bear against the lower edge of the gaugeplate to correctly position the unit 8.

Mounted on opposite sides of the upright frame 11 and spaced from eachother are an adjustable hone arm 14 and an adjustable grinder arm 15.The arm 14 is provided with slots 14:: and the arm 15 is provided withslots 15a to permit adjustment of the arms 14 and 15 with respect to theblade.

The hone arm 14 is formed with a forwardly and upwardly projectingbifurcated portion 16 through the legs of which is journaled a pin 17 tosupport one end or and provide a pivot for a yoke-shapedfinger-depressible lever 18 of the second order.

A spindle 19 with its axis perpendicular to the gauge plate 4 isrotatably mounted through a slidable sleeve hearing 20 positioned in thehone arm 14. A honing wheel 21 is fastened to the lower end of thespindle 19 by means of a screw 22.. In the instant invention, it ispreferable that the sleeve bearing 20 in which the spindle 19 rotates beslidable, but not rotatable in the hone arm 14. Rotation of the bearing20 is prevented by forming its upper portion as a square head 23, twosides of which bear against side walls 24 of the lever 18.

Iuxtaposed to the square head 23 of the bearing 28 is a trunnion block25 with its edges coextensive with the edges of the square head. Theblock 25 is drilled to permit passage of the spindle 19 therethrough. Apair of laterally disposed trunnion pins 26 project from the block 25and are journaled in the side walls 24 of the lever 18 substantiallymidway between the levers ends. A collar 27 is pinned to the uppermostend of the spindle 19 to retain the trunnion block 25 and the bearing 29between said collar and a shoulder 23 of the spindle.

The honing wheel 21 is engaged with the rotating knife 2 of the machineby pressing downwardly on the lever 18 at its end opposite that throughwhich the pin 17 is journaledh The lever 18 is pivoted on the pin tomove the co-operating trunnion block 25, the sleeve bearing 20, thespindle 19, and the honing wheel 21 downwardly toward the upper side ofthe cutting edge of the knife. The spindle 19, when the honing wheelcontacts the rotating knife 2, rotates in the sleeve bearing andtrunnion block 25. The latter two members, however, are unable torotate, their square sides being held against rotation by the side walls24 of the lever 18.

The honing wheel 21 may be held in contact with the knife 2 as long asdesired, and when the lever 18 is released, it is returned to itsoriginal inactive position by a return spring 29 located on the pin 17.

A shroud 30 is fastened to the spindle 19 at its lower end just abovethe honing wheel 21 to prevent abrasive dust from the honing wheel fromgaining access to the spindle. Figure IV illustrates a shroud which isrotatable with the spindle.

A dust shield 31 is fastened to the hone arm 14 and extendssubstantially around the shroud 30 to further protect the spindle 19from dust.

The grinding mechanism is substantially similar to the honing mechanism.It comprises a yoke-shaped finger-depressible lever 32 of the firstorder pivoted at its center on a pin 33 which extends through legs of abifurcated portion 34 extending rearwardly and upwardly from the grinderarm 15. A trunnion block 35 similar to the trunnion block 25 isjournaled in the side walls 36 of the lever 32 opposite the end of thelever which is depressed. Movement of the trunnion block 35 causes acorresponding movement of a sleeve bearing 37, a spindle 38, a grindingwheel 39, a shrould 40, and a collar 41 which co-operate therewith. Itwill be noticed that the axis of the spindle 38 is inclined with respectto the gauge plate 4. This accommodates proper engagement of thegrinding wheel 39 with the beveled underside 42 of the knife 2.

Since the lever 32 is pivoted at its center, depression of said leverwill engage the grinding wheel 39 with the knife by upward movement ofthe spindle 38, said spindle being so positioned by upward movement ofthe trunnion block 35 journaled in the side walls 36 of the lever 32.

It can be seen therefore, that both wheels 21 and 39 are engaged withthe knife 2 by downward pressure on their respective levers althougheach approaches and contacts the knife from opposite directions. Also,since the honing mechanism and grinding mechanism are independent fromone another, they may be operated separately or simultaneously, asdesired.

When the sharpening unit 8 is not attached to the gauge plate 4 inoperative position, it is stored in a bowllike hollow portion 43 of thecarriage 5 in an inverted position on a bracket 44 attached inside thecarriage substantially as shown in Figure VT. By removing a cover 45 ofthe hollow portion 43, the unit 8 may be attached to the bracket 44 withthe thumb screw 9 fitting in a slot in a manner similar to that in whichthe unit is positioned on the gauge plate 4. The thumb screw 9 is thentightened and the cover 45 replaced. The sharpening unit 8 remains inthe hollow portion 43 of the carriage 5 until it is again necessary tosharpen the knife 2.

Operation Let us assume that a grocer wishes to sharpen the knife of hiscommodity slicer, it having appeared a little dull during the lastslicing operation. He would proceed to remove the sharpening unit 8 fromits storage position in the carriage 5 by removing the cover 45,loosening the thumb screw 9, and withdrawing the unit from the bracket44 and the hollow portion 43 of the carriage.

Before the unit 8 can be placed in its operative position on the gaugeplate 4, the gauge plate must be moved to 'its lowermost position byrotating a gauge plate knob (not shown).

The sharpening unit 8 is then attached to the gauge plate 4 by fittingthe thumb screw 9 into the slotted portion 10 in the lowerright-handcorner of the gauge plate. Proper alignment of the unit 8 in operativeposition is accomplished by placing the lip 13 of the base portion 12 ofthe unit snugly against the lower edge of the gauge plate. By tighteningthe thumb screw 9, the unit 8 is firmly attached to the gauge plate ,4and the sharpening operation is ready to begin.

Rotation of the knife 2 is necessary in order to sharpen it with theinstant invention. The knife is operatively connected to a motor (notshown) in the housing 1. A toggle switch (not shown) permits current toflow to the motor. When said toggle switch is turned on, the motorcommences to operate and the knife 2 begins to rotate.

If it is desired to both grind and hone the knife, the

sharpening may take place in one of two ways. The grinding wheel 39 maybe engaged with the beveled underside 42 of the cutting edge of theknife 2 by pressing downwardly on the lever 32. As the wheel 39 contactsthe knife, rotation of the knife causes said wheel, its spindle 38, andthe other rotating parts to rotate in a direction opposite that in whichthe knife 2 rotates. The knife of the instant invention rotatescounter-clockwise, thereby producing a clockwise rotation in thegrinding wheel 39.

As the grinding operation progresses, a wire edge is turned upward onthe cutting edge of the knife. The lever 32 is then released and thelever 18 is pressed downwardly to engage the honing wheel 21 with theupper side of the edge of the knife 2.

The honing wheel 21 also rotates clockwise upon engagernent with theknife 2, and acts to turn down the wire edge raised by the grindingoperation. Here is a decided advantage which finger-engageablesharpening mechanisms have over other means of engaging the wheels withthe knife. A sense of touch on the lever 18 can tell the operatorexactly when the wire edge has been turned down and the knife 2 is assharp as possible. Prior art devices which were not finger-engageableoften turned down the wire edge too far by too much honing and furthercreated another wire edge on the underside of the knife, since theoperator could not feel when the knife was correctly sharpened. Turninga wire edge downward necessitated another grinding operation, andconsequently another honing operation. From the standpoint of length oflife of the blade, it can easily be seen that the life of a bladesharpened with the instant invention would be considerably longer thanone sharpened with prior art sharpening devices of the spring or camengageable type.

Another method of sharpening when both grinding and honing of the knife2 are desired is to press downwardly on both levers 18 and 32simultaneously, thereby engaging both the grinding and honing wheelswith the knife. In this way, a wire edge is not created, since bothwheels work toward a common edge. After a short period, the pressure onthe levers is lessened until both wheels are removed from engagementwith the knife. A very sharp cutting edge is produced by this method.Prior art devices of the spring-engageable type had no means by whichthe pressure of the wheels against the knife could be lessened.

Quite often a grocer wishes merely to hone his knife slightly. In thatcase, the honing mechanism alone is operated.

When the operator feels that his knife is sharp, he can test it by anyof the several methods which need not be expounded here. If, upontesting the knife, he feels it has been sharpened enough, he can proceedto remove the sharpening unit, replace it on the bracket 44 in thehollow portion 43 of the carriage 5, replace the cover 45, and commencehis slicing of a commodity.

The embodiment of my invention herein shown and described is to beregarded as illustrative only and it is to be understood that the invcntion is susceptible to variation, modification, and change within thespirit and scope of the snbjoined claims.

I claim:

1. A sharpener for the rotary knife of a commodity slicing machinecomprising, in combination, a grinding wheel adapted to engage one sideof the rotary knife, a honing wheel adapted to engage the other side ofthe rotary knife, means for rotatably supporting the wheels, andfinger-depressible means for independently engaging each wheel with therotary knife, said finger-depressible means comprising a lever of thefirst order operatively connected to the grinding wheel and a lever ofthe second order operatively connected to the honing wheel, wherebydepression of the levers in the same direction will cause the Wheels toengage the rotary knife from opposite directions.

2. A sharpener according to claim 1 wherein the levers are adjacentlylocated, whereby the levers may be depressed by two fingers of one hand.

3. A sharpener according to claim 1 which is detachably mountable on themachine.

4. A sharpener for the rotary knife of a commodity slicing machinecomprising, in combination, a frame, a hone arm adjustably attached tothe frame, a grinder arm adjustably attached to the frame, a honespindle rotatably mounted through a slidable sleeve bearing in the honearm, a honing wheel fixed to the end of the hone spindle nearest therotary knife, a hone pin on the hone arm, a hone lever having an endpivoted on the hone pin and attached between its ends to the slidablesleeve bearing, a grinder spindle rotatably mounted through a slidablesleeve bearing in the grinder arm, a grinding wheel fixed to the end ofthe grinder spindle nearest the rotary knife, a grinder pin on thegrinder arm, a grinder lever having an end pivotally attached to thegrinder spindle and pivoted between its ends on the grinder pin, wherebymovements of the free ends of the levers in directions generally towardthe plane of the rotary knife engages the wheels with the rotary knifefrom opposite directions.

5. A sharpener according to claim 4 wherein the levers are adjacentlylocated, whereby the levers may be depressed by two fingers of one hand.

6. A sharpener according to claim 4 which is detachably mountable on themachine.

References Cited in the file of this patent UNITED STATES PATENTS1,060,916 Luschka May 6, 1913 1,483,878 Hand Feb. 19, 1924 1,772,704Campbell Aug. 12, 1930 2,030,197 Campbell Feb. 11, 1936 2,486,797 MeyerNov. 1, 1949 FOREIGN PATENTS 609,867 Great Britain Oct. 8, 1948 988,143France Apr. 25, 1951

